The present disclosure relates to a centrifuge with a rotatable centrifugal drum having a stack of discs.
Separators of this type are known in many different embodiments, for example, from German Patent Document DE 200 10 743 U1.
The present disclosure relates to an improvement on this state of the art such that separators are created which have at least partially improved characteristics and new usage possibilities.
The present disclosure relates to a new type of centrifuge which has many different advantages in comparison with the state of the art.
The present disclosure relates to a centrifuge having at least two centrifugal drums which can respectively be rotated about two axes of rotation. One of the axes of rotation extends through the center of gravity of the centrifugal drums such that the axis of rotation is situated inside each of the at least two drum(s). An additional axis of rotation is situated outside the centrifugal drums. The two axes of rotation extending through the center of gravity may be aligned or may be parallel to one another in a plane. A disc stack is in each of the drums.
A separator or centrifuge with at least two drums which each rotate about two axes of rotation and which each have a stack of discs results in new effects in the interior of the centrifugal drums which can be utilized, for example, for optimizing the solids discharge.
From the state of the art, filter centrifuges are known, for example, which have two filter drums (German Patent Document DE 3131329 A1).
German Patent Document DE 3 092 579 also shows an evacuating system for open drums which can be rotated about an axis of symmetry and, during the evacuation, are tilted about a second axis extending through the drum.
German Patent Document DE 1 432 853 OS shows a method and a device for separating substances by gyrofugation. In such a case one drum is rotated about its axis of symmetry and is moved about another axis on a circular ring, which axis is inclined by approximately 45° with respect to the axis of symmetry.
Concerning the state of the art, German Patent Document DE 40 13 388 A1 and Belgian Patent Document BE 703747 are also cited which are more remote.
However, separators with more than one drum, with each drum having a disc stack and the drums being rotatable about more than one axis of rotation are not known to be disclosed or suggested in the state of the art.
According to the present disclosure, a centrifuge includes at least two centrifugal drums. One of the axes of rotation is situated inside the at least two centrifugal drums, and the other axis of rotation is situated outside the centrifugal drums. Thus, a centrifuge is obtained which can more easily be balanced than a centrifuge with only one centrifugal drum because the additional axis of rotation of the centrifugal drum is situated outside the centrifugal drum.
The present disclosure can be implemented in a compact and uncomplicated manner such that the first axes of rotation of the drums are each situated inside the drums and are congruent with an axis of symmetry of the drums. The second axis of rotation perpendicularly crosses the first axes of rotation. This arrangement can be implemented, for example, by a dumbbell-type distribution of the drums, the axis of symmetry of the drums in each case representing the first axis of rotation and the two drums being rotated in a dumbbell-type manner about the second axis of rotation. In this case, the solids are transported to the outside as a result of the rotation of the two drums about the joint second axis of rotation, without requiring auxiliary devices for this purpose. The disc stacks have an additional clarifying effect because they rotate about the first axis of rotation. As a result of the rotation about the second axis outside the disc stack, which is superposed on the rotational speed of the first axis, flow behaviors are also obtained which differ from those of the state of the art.
The at least two centrifugal drums have a double-conical construction, including two mutually oppositely oriented conical sections each being constructed at a respective end area, of the drum. One such end area is located adjacent to the second axis of rotation and the other such end area is located and distanced further away relative to the second axis of rotation. The two conical sections of each centrifugal drum are mutually connected by cylindrical sections.
A disc stack with conical discs and rising ducts is arranged concentrically with respect to the inflow pipe in the centrifugal drums. Solids from the feed or centrifugal material are separated in the disc stack and collected in the solids space (cylindrical) of the centrifugal drum. As a result of the rotation about the second axis A2, the solids are then transported to the outside. As a result of this construction, it becomes possible to convey the solids by rotation of the drums about the joint second axis of rotation completely automatically to the outside. A use of the system is conceivable for the purpose of clarification (solid/liquid) and/or of separation (liquid/liquid). As a result of the rotation about the first axis, the effect of the disc stacks is the same as in a normal separator. However the disc stacks can also have discs at the top. The rotational speed at the first axis corresponds to that of a separator.
Since it becomes possible to transport the solids without additional mechanisms out of the drum, in comparison to decanters, this means that neither a planetary gear nor a screw are to be provided for discharging the solids. This also eliminates wear.
In addition, because of the disc stack in the drums, an almost arbitrary clarification surface can be implemented. Mechanical limits as a result of natural frequencies can largely be avoided. It also becomes possible to mount self-cleaning sieve inserts. The energy requirement is relatively low because the solids outlet is situated in the center of the axis of rotation. By an open inlet with centrifugal support, overflowing can be avoided. However, not only open but also closed systems, such as centripetal pumps or the like, are conceivable.
In comparison to known separators, no hydraulic drum system has to be provided for the evacuation. Also, the clogging of nozzles can be avoided because the nozzle diameter can be large in comparison to systems with many small nozzles, and the energy requirement for the solids discharge in the center of the main axis of rotation is low. Under certain circumstances, backwards-oriented nozzles are even conceivable if they do not also rotate about the first axis. This can be implemented, for example, by floating ring seals. If the nozzles are arranged on a machine frame which rotates only about the second axis of rotation, this again lowers energy requirements.
However, it should also be noted that it is conceivable to connect the centrifugal drums behind one another with respect to the flow path of the centrifugal material. And, for example, it is possible to use one of the centrifugal drums for a preclarification and another centrifugal drum for the fine clarification which follows.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.